<template>
  <div class="app-container">
    <el-input
      v-model="filterText"
      placeholder="Filter keyword"
      style="margin-bottom: 30px"
    />

    <el-tree
      ref="tree2"
      :data="data2"
      :props="defaultProps"
      :filter-node-method="filterNode"
      class="filter-tree"
      default-expand-all
    />
  </div>
</template>

<script>
  export default {
    data() {
      return {
        filterText: '',
        data2: [
          {
            id: 1,
            label: 'Level one 1',
            children: [
              {
                id: 4,
                label: 'Level two 1-1',
                children: [
                  {
                    id: 9,
                    label: 'Level three 1-1-1',
                  },
                  {
                    id: 10,
                    label: 'Level three 1-1-2',
                  },
                ],
              },
            ],
          },
          {
            id: 2,
            label: 'Level one 2',
            children: [
              {
                id: 5,
                label: 'Level two 2-1',
              },
              {
                id: 6,
                label: 'Level two 2-2',
              },
            ],
          },
          {
            id: 3,
            label: 'Level one 3',
            children: [
              {
                id: 7,
                label: 'Level two 3-1',
              },
              {
                id: 8,
                label: 'Level two 3-2',
              },
            ],
          },
        ],
        defaultProps: {
          children: 'children',
          label: 'label',
        },
      }
    },
    watch: {
      filterText(val) {
        this.$refs.tree2.filter(val)
      },
    },

    methods: {
      filterNode(value, data) {
        if (!value) return true
        return data.label.indexOf(value) !== -1
      },
    },
  }
</script>
